Editor’s note: What follows is a conversation between Dave Rubin, host of the Rubin Report, and Professor Steve Davies, education director at the Institute of Economic Affairs in London, about when foreign intervention might be appropriate from a classical liberal perspective.

Dave Rubin: You think there is a situation where a libertarian could be for some intervention, basically.

Steve Davies: Yes. For any kind of libertarian/classical liberal, the question with foreign policy is which course of action is going to most maximize liberty, both in the country that is potentially doing the intervening, the U.S. for example, and the part of the world where the intervention might take place. That should be the guiding principle behind what your foreign policy is. What I would say, and I agree with a friend of mine, Randy Barnett, on this, is there’s nothing inherent or necessary about libertarian principles that means you must be a non-interventionist.

What I would argue and here perhaps I disagree slightly with Randy, is that the number of cases where the benefits of liberty will be so great that you would support intervention. It’s actually very, very slight. I would apply something like a just war principle. You have to show that really the benefit is bound to exceed the cost and this is knowable and the intervention could be done in a way that doesn’t systematically violate the human right. That’s quite a high bar.

Dave Rubin: Wait, let’s pause there for a second. How much does the benefit have to be for you and your society, not just the people that you’re potentially doing good for?

Steve Davies: Well, I think it’s more of the matter of the cost because if you think about intervention in foreign parts of the world, one of the main arguments against that from a libertarian or classical liberal position is that it is actually bad for liberty back home in the country doing the intervening to the extent that the United States becomes an empire and it is an empire, let’s not pussyfoot about this. That undermines republican institutions and liberty back home. This is not a new phenomenon.

Many of the things that led to the growth of the state in Great Britain were because of British intervention outside the rest of the world. The India office, which ran the Indian empire, was our first big modern department of states, and then transformed the rest of government by its example. Same thing’s happened in the United States.

Dave Rubin: Basically, you do these things over there, wherever there is, and then you actually need more state power at home —

Steve Davies: Well, not only that, it provides an example, so in order to have for example you need a really large military if you’re going to have a kind of global interventionist role, that inevitably does things like increase the role of military domestically, increases its purchasing power, it’s clout. Builds up the military industrial complex that Eisenhower warned against, has all kinds of bad effects. It also leads to the growth of the surveillance state, it leads to the growth of the police power of the state which we spoke about earlier which you might say is necessary for certain cases, but it’s certainly not to the degree about it now.

It just also generally gives out rulers ideas above their station, because if you have the mindset of, “Oh, we can go over and be this benevolent despot and transform the lives of these people in other parts of the world,” this tends to actually create a mindset. We think, “These people here in our own society, they could do without benevolent interference as well,” and that’s a very dangerous mindset.

Dave Rubin: Right, and somehow we always have money to do those adventures, but we never have money to deal with what’s happening here.

Steve Davies: Yeah, what a surprise.

Dave Rubin: Yeah, what could be happening there?

Steve Davies: You know, it benefits all kinds of people. The other quite shameful thing is that this typically involves sending young men from often poor backgrounds into harm’s way, when the children of the people making these decisions are certainly not joining the military and if they are, they’re probably not going to be sent into harm’s way in that way. Which I think is seriously disreputable. I wouldn’t rule out that there are certain cases where an intervention could be on balance, beneficial for liberty both at home and in the place where the intervention takes place, but I think that’s vanishingly very low probability. There are very few cases like that in my view.

Dave Rubin and Steve Davies discuss foreign intervention below